I have a page rank of 3 on my home page and until recently no page rank on any other pages.submitting Suddenly I have page rank on a number of pages on my navigational bar. The home page likely got page rank because I have a lot of links back to it via buying links to regular directories, article marketing, Squidoo and other similar efforts, stumble on ssubmitting articles to article directories and paid article distribution companies so a lot of effort at using text link keywords has been done on the home page which resulted in pr for that page . But the fer other pages that have pr nothing was done to increase pr. I link my home page text links and navigational bar to product pages to article pages and use to link article pages to each other but not they link back to product pages and text link to a few afflatus sites. That is one of 2 changes that could have made the other pages get pr that are not the home page I know of. There is one other thing that might have helped and that is on the article pages I linked keywords that when clicked on go directly to sales pages that are relevant to the article text link. Not knowing why the page rank has succored on some pages besides the home page makes it hard to know what to do to get page rank on the other pages that do not have any now or increase the page rank on the pages that now have it. If you think of any reasons in page rank for this increase on non home pages let me know.
Page rank is passed by links - presumably your homepage passed some page rank to the 2nd level pages that are linked in the nav on the homepage.
over time, all the pages will have PR. it just takes time and depends on how bany backlinks you have and how often google bot visits your site. having a sitemap helps google find the internal pages. if it is a blog, then use your DP recent blog post